She spent 30% of her time practicing yoga
Here, we want to calculate the percent of the time that was spent practicing yoga
The total amount of minutes spent working out will be;
25 + 10 + 15 = 50 minutes
From the question, she spent 15 minutes practicing yoga
So the percentage of the time she spent practicing yoga will be;
[tex]\begin{gathered} \frac{15}{50}\text{ }\times\text{ 100} \\ \\ =\text{ 30 percent} \end{gathered}[/tex]